Complex forming polymers

ABSTRACT

COMPLEX FORMING POLYMERS HAVING REPEAT UNITS   2-(PYRID-2-YL-L-)PYRIDINE   JOINED TO EACH OTHER BY POLYVALENT LINKING GROUPS, WHERE L IS A DIRECT BOND OR AN O, S, CO, CHR1 OR NR1 LINK (R1 BEING HYDROGEN OR ALKYL) AND THE PYRIDYL RINGS MAY BE SUBSTITUTED BY ALKYL OR LINKED TO EACH OTHER AT POSITIONS ORTHO TO THE L LINK BY A -CR1=CR1 GROUP, ARE USEFUL FOR COMPLEXING NON-ALKALINE METAL ATOMS. THEY WILL FORM COMPLEXES IN AN ACIDIC MEDIUM AND WHEN THE METAL IS ITSELF ALREADY PART OF A COMPLEX ION. THE COMPLEXED POLYMERS ARE USEFUL AS CATALYSTS AND, AS ARE THE COMPLEX FORMING POLYMERS, AS VARNISHES FOR COATING METAL. THE POLYMERS ARE PREPARED BY A VARIETY OF VINYL-TYPE POLYMERIZATIONS AND POLYCONDENSATIONS. PARTICULARLY USEFUL INTERMEDIATES 2-(4-(H-CO-AR-CH=CH-)PYRID-2-YL),4-(H-CO-AR-CH=CH-)PYRIDINE WHERE AR IS ARYL ARE PREPARED FROM THE ARYL DIALDEHYDE AND 4,4&#39;&#39;-DIMETHYL-2,2&#39;&#39;-DIPRIDYL.

United States Patent Ofice 3,810,888 Patented May 14, 1974 U.S. Cl.260-240 D 3 Claims ABSTRACT OF THE DISCLOSURE Complex forming polymers,having repeat units joined to each other by polyvalent linking groups,where L is a direct bond or an O, S, CO, CHR or NR link (R beinghydrogen or alkyl) and the pyridyl rings may be substituted by alkyl orlinked to each other at positions ortho to the L link by a --CR =CRgroup, are useful for complexing non-alkaline metal atoms. They willform complexes in an acidic medium and when the metal is itself alreadypart of a complex ion. The complexed polymers are useful as catalystsand, as are the complex forming polymers, as varnishes for coatingmetal. The polymers are prepared by a variety of vinyl-typepolymerizations and polycondensations. Particularly useful intermediateswhere Ar is aryl are prepared from the aryl dialdehyde and4,4'-dimethyl-2,2-dipyridyl.

a -L- a or ill a; B

L represents a valency bond or the divalent radical --O-,

S, CO, CHR or NR R being hydrogen or a lower alkyl group, and thesymbols a, a and a each represent hydrogen or a valency bond, the numberof these symbols representing a valency bond being 1 or 2, or a loweralkyl group, or a, and a, together represent the radical CR =CR the saidunits of Formula I being joined together by one or more polyvalentradicals R.

In the case where a and a represent hydrogen and L represents a valencybond, the unit of Formula I is more precisely called a dipyridyl unit;in the case where a; and u together represent the CH=CH radical and L inwhich:

represents a valency bond, the unit of Formula I is more preciselycalled o-phenanthroline unit." It is of course understood that in thesetwo cases the representation of these units by the formulae:

is purely formal in character and that, in reality, the electrons aredelocalized in accordance with the classical state of aromatic nuclearsystems.

The polyvalent radical R, which is a linking agent may representradicals R or R as set out below:

R represents an organic or inorganic divalent radical which can, forexample, consist of a radical or of a succession of several radicals R Rand Y, as follows:

R represents a saturated or unsaturated, linear or branched alkyleneradical which may optionally carry hydroxyl or oxo substituents and mayoptionally carry alkano or alkeno bridges, with the total number ofcarbon atoms of the radical R being preferably less than 12,

R represents an arylene radical such as phenylene, or a divalentheterocyclic radical, and

Y represents an R being a lower alkyl radical or an aryl radical such asphenyl.

R represents a polyvalent macromolecular radical, for example, offormulae:

in which K represents a trivalent organic radical, Q represents atetravalent organic radical, m represents a positive integer, and K, Qand m are such that -(-KH-} and (QHgh represent polymers such aspolyolefins, polyethers, polyamides, polyesters, polyimides,polyurethanes, vinyl polymers or acrylic polymers.

The complex-forming polymers derived from linking agents of type R arecalled complex-forming polymers of type P and the derivatives of linkingagents of type R;

are called complex-forming polymers of type P According to a first groupof methods of preparation, polymerization is carried out employing atleast one dinitrogenous monomer having at least one suitable reactivegroup (by a dinitrogenous monomer we mean a monomer of which all or atleast part of the structural skeleton is identical to the skeleton ofthe compound of formula:

a." (II) in which a, a; and a' have the same meanings respectively as a,a and a in Formula 1, above except they do not represent a valencybond).

This polymerization can be a so-called vinyl polymerization or apolycondensation.

If a vinyl polymerization is carried out, the dinitrogenous monomer maybe derived from the compound of Formula H and have one or moreolefinically unsaturated substituents, such as substituents of formulae:

/C=Cll or C=(|J(IJH-- S3 S3 S; S8 S4 in which S S S and S which may beidentical or different, each represent hydrogen or a lower alkyl group.

If a polycondensation is carried out, the dinitrogenous monomer employedmay be derived from the compound of Formula II and have one or moresubstituents which can participate in polycondensation reactions.

For the purpose of preparing complex-forming polymers of type P themonomers preferably are of formula:

N N Q Q f (11 02 f2 (III) in which 1; and f which may be identical ordifferent, each represent reactive groups of formula -R'-Z, wherein Rrepresents a valency bond or a radical or a succession of radicals suchas R R and Y, of which the two free valencies are carried by carbonatoms, and Z represents a group such as formyl, amino, hydroxyl,hydroxycarbonyl, chlorocarbonyl, or isocyanato and can also representhydrogen in the case where R represents a methylene radical.

The dialdehyde monomers, of Formula IH, in which f and 1: have theformula 'R'CHO, can be polycondensed with ketones or amines.

Their polycondensation with ketones can, for example, be carried out inaccordance with the techniques described in Belgian Pat. No. 714,325. Ifthe ketone has the formula:

in which R and R which may be identical or different, each representalkyl, cycloalkyl or aryl radicals or optionally together form adivalent alkylene radical, the complex-forming polymer according to theinvention then comprises repeat units of formula:

in which the suflix hy placed under a double bond indicates that thelatter can optionally be in the hydrated form (-CHOHCH Thepolycondensation of a dialdehyde monomer of Formula III in which f and fhave the formula -R'CHO with a diamine can be effected in accordancewith the various techniques described by G. F. d'Alelio et al. (I.Macromol. Sc. A; (2) 237-333 (1968)). If the diamine employed has theformula NH -R NH in which R, is a radical or a succession of radicalssuch as R R and Y, of which the two free valencies are carried by carbonatoms, the complex-forming polymer so obtained comprises repeat units offormula:

which and f represent --R'NH radicals is polycondensed with adianhydride of formula:

in which R represents a tetravalent organic radical containing at leasttwo carbon atoms, the polymer thus obtained comprises repeat units offormula:

If a diamine monomer of Formula III in which f, and f represent -R-NHradicals is polycondensed with a diisocyanate of formula OCN'R NCO inwhich R, has the meanings given for R a polymer with urea units isobtained having repeat units of formula:

Dimethylated monomers of formula:

f--N N 1 CH1 1 a: CH;

can give rise to polycondensates in various ways.

Under the dehydrogenating action of sulphur, they can give rise tocomplex-forming polymers having repeat units of formula:

N N L a1 02 Hr- This polycondensation can be carried out in accordancewith a technique similar to that known for the picolines (H. I. Thayeret al., I. Am. Chem. Soc. 70 2330-3 1948) With dianhydrides of formula:

the dimethylated monomers of Formula IV can give rise to complex-formingpolymers comprising repeat units of formula:

This latter polycondensation can be carried out by simple heating of themixture of the reagents, preferably in the presence of a dehydratingagent and at a temperature above 100 C.

The dimethylated monomers of Formula IV can furthermore be polycondensedwith dihalogenated derivatives of formula X-iR X wherein X represents ahalogen atom and R7 represents a divalent radical as defined above. Theresulting complex-forming polymers have repeat units of formula:

polycondensed with olefines and, more particularly, with divinylderivatives of formula CH2 CH2 in which R can represent a valency bondor a divalent radical such as R or R The resulting complex-formingpolycondensates have repeat units of formula:

| H: 01 at Hg-CHn-CHz-Rm-CHa-CHz- This polycondensation can be achievedin accordance with a technique similar to that known for the picolines(R. Wegler et a1. Ber. 83, 6-10 (1950)).

Dihydroxy monomers of Formula III in which f and f represent -R'-OHradicals can give rise to complexforming polymers by reaction withdiacids, dianhydrides or dichlorides of acids (to give polyesters) ordiisocyanates (to give polyurethanes).

Dicarboxylic monomers of Formula III in which f and f represent -R'COOHradicals can give rise to complex-forming polymers by reaction withdiols (to give polyesters) or diamines (to give polyamides).

Isocyanato monomers of Formula III, in which f and f represent -R'-NCOradicals can give rise to complexforming polymers by reaction with diols(to give polyurethanes) or diamines (to give polyureas).

According to a further method of preparing the complex-forming polymersaccording to the invention, a dinitrogenous monomer is attached to apreviously produced polymer. It is, for example, possible to react apolymer of formula Examples of radicals f and 'f;; include radicalshaving carboxy/hydroxyl, chlorocarbonyl/hydroxyl and anhydride/hydroxylgroups, which give rise to polyesters, carboxyl/amino andchlorocarbonyl/amino which give rise to polyamides, hydroxyl/isocyanatewhich gives rise to polyurethanes, and hydroxyl/ aldehyde which givesrise to polyacetals.

In particular, a complex-forming polymer of type P can be prepared byreacting a polymer with hydroxyl groups, such as a homopolymer orcopolymer of vinyl alcohol, in the presence of an acid, with adinitrogenous monomer having at least one aldehyde group, such as acompound of formula:

This acetalization can optionally be carried out in the presence ofother aldehydes, such as formaldehyde, or their precursors, such astrioxymethylene.

The complex-forming polymers according to the invention can, dependingon their nature and their method of preparation, be obtained in thesolid state or in solution or in suspension; they are preferably storedin the moist state, in solution or in suspension.

From amongst the numerous polymer types described above, the preferredpolymers according to the invention are:

(1) Polymers having repeat units:

RA- QCQ wherein R represents a divalent radical:

R'cH=c-O0c=cH-R'- hy hy in which R and R represent hydrogen or an alkylradical with l to 4 carbon atoms or together form an alkylene radicalhaving 2 or 3 carbon atoms, and R represents the --CH=CH--Ar' radical,Ar being the m-phenylene, p-

phenylene or p-diphenylene group, and by indicates that the double bondmay optionally be hydrated or:

(b) --NHC0-NHR9NH-C0NH in which R, has the formula:

CH: (IIHI Ha)s- In which n has a value of 1 to 10, or (d) C O (2)Polymers having repeat units radicals R wherein Ar and by have thesignificance given above.

The preferred processes for preparation of the polymers are thosedescribed above in which the reagents are chosen to give the preferredproducts indicated above.

The present invention also relates to the application of thecomplex-forming polymers described above to the preparation of additioncompounds, especially salts of complex-forming polymers, and ofcomplexed polymers. The salts of complex-forming polymers are obtainedby linking acids not containing a metal atom to the units of Formula Iof the complex-forming polymers. More precisely, these salts may beprepared by reaction of the acid with the complex-forming polymer. Thisreaction can be carried out either by immersing the solid complexformingpolymer in a solution of the acid or by mixing a solution of the acidand a solution of a complex-forming polymer.

The complex polymers are macromolecular compounds containing repeatunits of formula:

G G N N o a a: a

linked to one another by one or more linking agents R, the meanings ofR, a, a a and L being the same as those given above, and G being anon-alkaline metal atom or an ionic compound, such as salts or acidscontaining at least one non-alkaline metal atom.

The coordination bonds indicated in Formula V join the nitrogen atoms tothe metal atom contained in G. If G represents a salt, the non-alkalinemetal atom can be contained either in the anion or in the cation.

If G represents an ionic compound, the metal atom which is directlylinked to the nitrogen atoms by coordination bonds can optionally andadditionally comprise other coordination, covalent or electrovalentbonds which link it to other ions, atoms or molecules.

Examples of salts G which can be used include ordinary metal salts suchas the halides, nitrates, sulphates, phosphates, formates, acetates,propionates and stearates; salts which contain a complex cation such asthe oxo-cations derived from titanium, vanadium, zirconium andmolybdenum, hafnium, niobium, tungsten and uranium; salts containing acomplex anion such as PdCl, and, more generally, anionic metal complexesof the halides, cyanide, thiocyanate, thiosulphate and orthophosphateanions.

Examples of acids containing at least one non-alkaline metal atom,include H PtCl and H PdCl, and, more generally, the acids correspondingto the previously quoted salts containing a complex anion.

The complexed polymers described above can additionally, or optionallycomprise repeat units of Formula I which have been salified by an acidwhich does not contain a metal atom, and can hence partly constitutesalts of complex-forming polymers.

Complexed polymers comprising repeat units of Formula V, in which Grepresents an ionic metal compound, can be prepared by bringing togethera solution of an ionic compound with the complex-forming polymer or oneof its salts, in the solid state or in solution.

If a complexed polymer derived from an ionic compound is preparedstarting from a solid complex-forming polymer, various techniques can beemployed such as:

(a) the complex-forming polymer, reduced to a fragmented form, such as apowder or granules, is stirred in an aqueous solution containing anionic compound, and the solid material, which is the desired complexedpolymer is then isolated.

(b) a solution of an ionic compound is brought into contact with thesolid complex-forming polymer in accordance with conventionalliquid-solid chromatography techniques.

If a complexed polymer derived from an ionic compound is preparedstarting with a solution of a complexforming polymer, it is advantageousto bring this solution together with a solution of the ionic compound.Depending on the nature of the solvents employed, of the complex-formingpolymer and of the metal ion, the complexed polymer obtained can eitherremain in solution or precipitate. Depending on the particular case, thecomplexed polymer is isolated either by filtration or by distillation ofthe solvents and removal of the non-complexed ions by washing, or byprecipitation with a non-solvent followed by a filtration.

The preparation of complexed polymers comprising repeat units of FormulaV in which G represents a metal atom, is usually effected by reductionof the metal atoms of a complexed polymer comprising repeat units offormula:

a G i a L -a a in (IT a (V his) in which 6' represents an ionic compoundderived from the metal G. This reduction is usually effected withhydrogen, at a temperature between 0 C. and the decompositiontemperature of the complex-forming polymer.

The complex-forming polymers according to the invention are particularlyvaluable in numerous industrial ap plications, firstly because of theirability to complex metal ions excluding alkaline ions, and of doing soeven in an acid medium, secondly, because the complex formation takesplace without ion exchange, and finally, because of their ability tocomplex anions which are themselves complex.

Typical industrial applications include:

(a) the extraction of precious metals, of rare earths and of radioactiveelements such as uranium from their minerals,

(b) the separation of radioactive caesium from other metals,

(c) the separation of various non-alkaline metals from one another: thecomplex-forming polymers according to the invention complex certainmetals more strongly than others,

((1) the recovery of chromium salts from tannery waste liquors,

(e) the demineralization of organic solvents without introducing foreignions, for the purpose of preparing dielectric liquids, and

(f) the purification of industrial efiluents. It is known that theactivity of bacteria used to destroy organic waste material inindustrial effluents can be inhibited by certain metal ions such as thecupric ion. The presence of frequently large amounts of alkaline ions inthese effiuents prevents the use of ion exchange resins of theconventional type for the removal of these undesired ions. Thecomplex-forming polymers according to the invention on the other handcan advantageously be used to remove the undesired ions in thesecircumstances.

After extraction of the metal ions from the medium in question, theresulting complexed polymers can be recon'verted into complex-formingpolymers, for example by elution. The eluant may be a strong acid or acomplex-forming agent such as ethylene diamine orethylenediaminotetraacetic acid.

The complexed polymers comprising repeat units of Formula V, in which Grepresents a metal atom, can be used as catalysts, especially inhydrogenation, dehydrogenation and isomerization reactions.

The complexed and complex-forming polymers according to the inventioncan also be used as varnishes for coating metals.

The present invention also provides dialdehydes of Formula III in whicha and a are hydrogen atoms and f and f represent R'-CHO groups.

More particularly, these dialdehydes have the formula:

in which Ar represents a divalent radical comprising at least onearomatic nucleus, preferably the m-phenylene or p-phenylene radical, ora radical of general formula:

(VII) CHO wherein Ar has the previously indicated significance. Themolar ratio of dialdehyde to dimethyldipyridyl is usually between 1:1and 5:1 and they may be heated to a temperature generally above 100 C.,preferably above 130 C., but below the degradation temperature of thereagents and of the reaction product. Generally, the reactiontemperature does not exceed 200 C.

To obtain optimum yields, it is advantageous to incorporate adehydrating agent which is inert towards the reagents into the reactionmedium. To avoid local overheating of the reaction medium, it isadvantageous to carry out the process in a medium which is a solvent forthe reagents. These two procedures can be combined by incorporating intothe reaction medium a fatty acid anhydride derived from an acidpreferably possessing less than 12 carbon atoms. Acetic anhydride is onesuch anhydride which is readily available in industry.

After reaction, the dialdehyde of Formula VI can be isolated by variousmethods, especially by selectively dissolving the unreacted products,for example by means of volatile solvents such as alcohols, followed byfiltration. The dialdehyde obtained can be recrystallized using polarsolvents such as dimethylformamide or N-methylpyrrolidone-2.

The dialdehydes according to the invention can be used as reagents inmineral analysis.

The following examples are given to illustrate the invention.

EXAMPLE 1 A complex-forming polymer of the aldehyde/ketone type isprepared:

(A) In a first stage, 4,4'-bis(p-formylstyryl)-2,2'-dipyridyl isprepared by condensation of 4,4'-dimethyl-2,2'- dipyridyl andterephthaldehyde.

55 g. of 4,4'-dimethyl-2,2'-dipyridyl, 121 g. of terephthaldehyde and180 g. of acetic anhydride are introduced into a 500 cm. flask fittedwith a reflux condenser. The mixture is heated under reflux for 12 hoursand filtered hot; the precipitate is washed with 600 cm. of boilingacetic anhydride and then with 500 cm. of boiling pyridine and is driedat 50 C. under 200 mm. of mercury pressure for 12 hours. The resultingsolid weighs g. It is dissolved hot in 500 cm. of N-methylpyrrolidone(NMP), the solution is cooled and the product is filtered off, washedwith cm. of NMP and dried under 200 mm. of mercury pressure at 50 C. for12. hours.

79 g. of 4,4-bis(p-formylstyryl)-2,2'-dipyridyl of formula:

are obtained.

(B) In a second stage, this dipyridyl derivative is polycondensed withcyclohexanone.

14.0 g. of 4,4-bis(p-formylstyryl)-2,2-dipyridyl and 900 cm. ofdimethylformamide (DMF) are introduced into a one litre Erlenmeyerflask. The dialdehyde is dissolved by boiling the mixture. Thereafter,boiling is continued and 3.68 g. of cyclohexanone are first added,followed by 200 cm. of sodium hydroxide solution (2.5 N) added dropwiseover the course of 1 hour. The mixture is filtered hot. The precipitateis washed with 2 litres of water and dried at 50 C. under 200 mm. ofmercury pressure for 12 hours.

12.6 g. of a yellow-brown powder which is insoluble indimethylformamide, dimethylsulphoxide and acids and which comprisesrepeat units of formula:

=CHOCH=CH CH=CHOCH= y by in which the suflix hy has the samesignificance as given previously, are obtained.

(C) 0.1 g. of the complex-forming polymer prepared as described inparagraph B is stirred, at about 20 C., with 50 cm. of water in which 5micromols of cupric sulphate and 3.125 millimols of sodium sulphate havebeen dissolved. After 12 hours stirring, 1.5 micromols of cupric saltand the amount of sodium salt initially employed remain in solution. I

(D) 0.25 g. of the complex-forming polymer prepared as described inparagraph B is stirred, at about 20 C., with 50 cm. of water in which 1millimol of uranyl acetate has been dissolved. After 12 hours stirring,0.046 millimol of uranyl salt remains in solution.

(E) 0.25 g. of the complex-forming polymer prepared as described inparagraph B is stirred, at about 20 C. with 50 cm. of water in which 1millimol of cupric chloride has been dissolved. After 12 hours stirring,0.195 millimol of cupric salt remains in solution.

(F) The procedure described in paragraph D is repeated, replacing theuranyl acetate by cupric acetate and the water by ethyl alcohol.

After 12 hours stirring, 0.056 millimol of cupric salt remains insolution.

EXAMPLE 2 A complex-forming polymer is prepared by polycondensation ofthe aldehyde/ketone type.

1.5 l. of dimethylformamide and 15 g. of4,4'-bis(pformylstyryl)-2,2'-dipyridyl are introduced into a 2 litreflask and the mixture boiled so that the dialdehyde dissolves. Thesolution is cooled to 55 C. and 2.32 g. of acetone and 15 cm. of a 40%by weight aqueous solution of tetrabutylammonium hydroxide added. A newsolution, which in the present example and in the following example isdescribed as a collodion, is obtained. This collodion is concentrated toa volume of 200 cm. by distillation under 20 mm. of mercury pressure andis then poured into one litre of ethyl ether. The resulting precipitateis filtered off, washed with one litre of water and dried at 50 C. under200 mm. of mercury pressure for 12 hours.

14.5 g. of a polycondensate comprising repeat units:

are obtained.

EXAMPLE 3 CH=CH is observed.

(B) The procedure of paragraph A is repeated replacing cupric nitrate byBa(NO BaCl CaC1 MgCl MgSO Ca(NO SrCl CuCl CuSO Cu(CH COO) CoCl Co(NCo(CH COO) NiSO VOSO and TiOSO These various salts give results similarto those obtained with cupric nitrate.

(C) The preceding experiment is repeated with MnSO and CrCl Theprecipitate of complexed polymer is only obtained on cooling to 20 C.

(D) The procedure described in paragraph A is repeated, replacing thecopper salt by hydrochloric acid. A precipitate of a salt ofcomplex-forming polymer is obtained at 50 C.

EXAMPLE 4 A complex-forming polymer is prepared by polycondensation of adiisocyanate and a diamine.

25 cm. of freshly distilled dimethylformamide (DMF) and 4.64 g. of4,4'-diamino-2,2-dipyridyl are introduced into a 250 cm. flask equippedwith a stirrer, a dropping funnel and a thermometer. 25 cm. of DMF inwhich 6.25 g. of 4,4'-diisocyanatodiphenylmethane have previously beendissolved are then run into the flask over the course of 2 minutes.After 30 minutes, the reaction mixture is poured into 800 cm. of water.The mixture is filtered, the precipitate is washed with 1000 cm? of N/sulphuric 12 acid and then with 200 cm. of water, and dried at 50 C.under 200 mm. of mercury pressure. 11.2 g. of a polycondensatecomprising repeat units of formula:

EXAMPLE 5 400 cm. of dimethylformamide and 4.16 g. of 4,4'-bis(p-formylstyryl)-2,2'-dipyridyl are introduced into a one litreErlenmeyer flask, the mixture boiled to dissolve the dialdehyde andallowed to cool to 60 C. 1.08 g. of cyclohexanone and 10 g. of a 40% byweight aqueous solution of tetrabutylammonium hydroxide are then added.This solution, which has a blood-red color, is called solution A.

A solution B is prepared by dissolving 4.76 g. of cobalt (II) chloridehexahydrate in 200 cm. of dimethylformamide at 60 C.

The two solutions A and B are heated to 60 C. and B is then poured intoA. The mixture is cooled and filtered. The precipitate is washed withwater and dried in vacuo (200 mm. of mercury pressure) and at ambienttemperature in a desiccator containing phosphorus pentoxide. 7.6 g. of acomplex-forming polymer comprising repeat units of formula:

are obtained.

EXAMPLE 6 A complex-forming polymer is prepared by polycondensation of adianhydride and a diamine.

6.2 g. of 4,4-diamino-2,2'-dipyridyl, 7.28 g. of pyromellitic anhydrideand cm. of dimethylacetamide are introduced into a 250 cm. flaskequipped with a stirrer, a thermometer and a reflux condenser separatedfrom the ambient atmosphere by means of a tube packed with phosphoruspentoxide.

The mixture is heated to 70 C. and 10.2 g. of acetic anhydride and 0.79g. of pyridine are added. The temperature is maintained for 30 minutesand the reaction mixture is poured into 2 liters of water. Theprecipitate is filtered, washed with 2 liters of water and then driedfor 12 hours at 50 C. under 200 mm. of mercury pressure.

13.25 g. of a complex-forming polymer containing repeat units offormula:

are obtained.

EXAMPLE 7 300 cm. of freshly distilled pyridine, 18.4 g. of 4,4'-dimcthyl-2,2-dipyridyl and 12 g. of sodarnide are introduced into a 500cm. flask equipped with a stirrer, a dropping funnel and a refluxcondenser.

The mixture is stirred for 4 hours at ambient temperature and 23 g. of1,5-dibromopentane are then added dropwise. The mixture is heated underreflux for 12 hours and filtered and the product is then successivelywashed with 1000 cm. of water, 500 cm. of ethyl alcohol, 250 cm. of Nhydrochloric acid and 250 cm. of water and finally dried at 50 C. under200 mm. of mercury pressure for 12 hours.

13.5 g. of a complex-forming polymer having repeat units of formula:

are obtained.

EXAMPLE 8 Three solutions A, B and C as defined below are mixed in a 500cm. Erlenmeyer flask:

Solution A is 0.4 g. of 4,4-bis(p-formy1styryl)-2,2-dipyridyl dissolvedin 40 cm. of dimethylsulphoxide (DMSO). Solution B is 2 g. of polyvinylalcohol (saponification number: 100) dissolved in 40 cm. of DMSO.Solution C is 2.5 N aqueous hydrochloric acid.

A fourth solution containing 16 g. of trioxymethylene dissolved in 120cm. of DMSO is thereafter added to the mixture of solutions A, B and C.

The resulting mixture is cast onto a glass plate 12 cm. x 25 cm. andkept for 48 hours at 55 C. under an absolute pressure of 200 mm. ofmercury. A film of complexforming polymer consisting of polyvinylalcohol acetalized and crosslinked by bis(p-formylstyryl)dipyridyl andby formaldehyde is obtained; this complex-forming polymer has the unitslinked to one another by macromolecular radicals having repeat unitsWhen immersed in an aqueous solution of cupric sulphate, this filmbecomes green. This color disappears on washing with ethylene diamine.

EXAMPLE 9 13 g. of p-divinylbenzene, 18.4 g. of 4,4'-dimethyl-2,2-dipyridyl and 140 cm. of pyridine are introduced into a 500 cm. flaskequipped with a stirrer and a reflux condenser. The mixture is heated to118 C. 46 mg. of so dium are added and heating is continued for afurther 15 hours. The mixture is cooled and evaporated at 40 C. under200 mm. of mercury pressure. The residue is ex tracted in a Kumagawaextractor with 400 cm. of ethanol for hours. The solid which remains isdried at 50 C. under 200 mm. of mercury pressure. 8 g. of acomplexforming polymer having repeat units of formula:

are obtained.

The complex-forming polymer also contains cross-linkings between chains,due to the divinylbenzene.

EXAMPLE 10 (A) A complex-forming polymer is prepared by polycondensationof the aldehyde/ketone type. i

1.7 l. of dimethylformamide (DMF) and 41. 6 g. of4,4'-bis(p-formylstyryl)-2,2'-dipyridyl are introduced into a 5 literflask equipped with a reflux condenser and a dropping funnel. Themixture is boiled to allow the dialdehyde to dissolve, and whilst beingkept at the boil, 6.4 g. of acetone dissolved in 50 cm. of DMF followedby cm? of aqueous 2.5 N sodium hydroxide solution, added dropwise in 1hour 30 minutes are added successively. The mixture is cooled to 50 C.and 2 liters of water at ambient temperature are added whilst stirring.The whole mixture is filtered and the precipitate is washed with '6liters of water and stored moist. The complexforming polymer obtainedhas repeat units of the same formula as that of Example 2.

Various complex-forming experiments are carried out with thiscomplex-forming polymer in suspension as fol.- lows:

(B) A complexed polymer containing palladium of degree ofoxidation-|-II(PdII) is prepared.

10.36 g. of the complex-forming polymer are stirred, at about 20 C.,with 500 cm. of water in which 18 millimols of hydrochloric acid and anamount of PdII chloride corresponding to 6500 microgram atoms ofpalladium have been dissolved. After 12 hours stirring, 50 microgramatoms of palladium remain in solution.

The complexed polymer containing PdII is filtered off.

(C) A complexed polymer containing palladium of degree of oxidation zerois prepared.

0.085 g. of the polymer prepared as described in paragraph B are mixedwith 0.915 g. of glass beads; the mixture is introduced into a 2 cm.reactor at 350 C.; a stream of nitrogen of 0.5 l./hour is passed throughthis reactor for 15 minutes followed by a stream of hydrogen of the sameflow rate for the same time, followed again by a stream of nitrogen for15 minutes. A polymer containing palladium of degree of oxidation zerois obtained.

(D) 3.79 g. of the complex-forming polymer prepared as described inparagraph A are stirred, at about 20 C., with 100 cm. of an aqueoussolution of chloroplatinic acid, H PtCl containing 1.2 milligram atomsof platinum per litre. After 12 hours stirring 0.04 milligram atom ofplatinum per litre remains in solution.

(B) 1.09 g. of the complex-forming polymer prepared as described inparagraph A are stirred, at about 20 C., with 50 cm. of water in which100 micromols of cupric nitrate and 5 millimols of nitric acid have beendissolved. After 12 hours stirring, 1.8 micromols of cupric salt remainin solution and the pH is 1.0.

(F) 0.965 g. of the complex-forming polymer prepared as described inparagraph A is stirred, at about 20 C., with 50 cm. of water in which100 micromols of cupric nitrate and 50 millimols of sodium nitrate havebeen dissolved. After 12 hours stirring, 1.15 micromols of cupric saltand the amount of sodium salt initially employed remain in solution.

(G) 1.109 g. of the complex-forming polymer prepared as described inparagraph A are stirred, at about 20 C., with 50 cm. of water in which100 micromols of ferric nitrate have been dissolved. After 12 hoursstirring, 0.65 micromol of ferric salt remains in solution.

EXAMPLE 11 4 g. of 4,4-dimethyl-2,2-dipyridyl and 12 g. ofterephthaldehyde are introduced, under an inert atmosphere, into a 250cm. flask equipped with a reflux condenser. The mixture is heated to C.for 20 hours and Washed with 400 cm. of boiling ethanol. The residue isrecrystallized from 100 cm. of N-methylpyrrolidone-2 and then driedunder 200 mm. of mercury pressure at 50 C.

15 4.5 g. of 4,4'-bis(p-formylstyryl)-2,2-dipyridyl of formula:

are obtained.

We claim: 1. A dialdehyde of the general formula in which Ar representsa divalent radical comprising at least one aromatic nucleus.

16 2. A dialdehyde according to claim 1 in which the radical Arrepresents a m-phenylene or p-phenylene radical or a radical of formulaReferences Cited Sasse et al.: Chemical Abstracts, vol. 55, cols. 15479to 15480 (1961).

Cheuychit et al.: J. Chem. Soc., 1964, pp. 4447 to 4560.

JOHN D. RANDOLPH, Primary Examiner US. Cl. X.R.

26064, 75 N, 77.5 AQ, 78 R, 283 R, 294.8 G, 295 R, 296 D; 4232, 53, 179

UNITED STATES PATENT OFFICE CERTIFICATE OF CORREQHON Patent No.3,810,888 Dated May 14, 1974 ln ventofls) Robert Chapurlat and EmileKuntz it is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

In the heading of the patent after the International Classification,there should be Claims priority, appl-ications France, July 28, 1969,69/25747 and August 26, 1969, 69/29196.

Signed and sealed this 18th day of February 1975.

(SEAL) v I Attest:

r C. MARSHALL DANN RUTH C. MASON I Commissioner of Patents AttestingOfficer and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3 8'10 888 Dated May 14 1.974

IriQIentor(s) Robert Chapurlat and Emile Kuntz It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In the heading of the patent after the International Classification,there should be Claims priority,

applications-France, July 28, 1969, 69/2574? and August 26, 1969,69/29196.

Signed, and. sealed this 18th day of February 1975.

(SE Attest:

t C. MARSHALL DANN I RUTH C. MASON Commissioner of Patents AttestingOfficer and Trademarks

